The long-range objectives of the proposed investigations are: (1) To determine the mechanism or mechanisms via which viruses such as bacteriophage T4 are able to take over the metabolic machinery of their host cells; (2) To elucidate the genetic control of (a) Recombination, (b) Homocatalytic expression, and (c) To examine the role of the host- cell membrane or other intracellular micro-environments, if any, in the control of homo- and/or hetero-catalytic expression of foreign genomes such as those of viruses. Immediate goals are the elucication of (1) The biological significance of and mechanism of nuclear disruption, movement of host DNA from a largely central location in the host cell into tight juxtaposition with the cell membrane; (2) The complete pathway of degradation of the host chromosome; and (3) The mechanism and genetic control of the "unfolding" of the host chromosome following infection of E. coli with bacteriophage T4. The ultimate goal is a more complete understanding of the interactions between infecting bacteriophage genophores and host cell.